Underground space utilisation and new town development: Experiences, lessons and implications

In the urbanisation process of the past few decades, the use of urban underground space (UUS) has contributed to new town developments in many cities in the world. This offers an opportunity to map out and systematically describe the potential contributions of UUS for transport, land use, economic, environmental and social development in new towns for planners, designers and policy-makers to consider. This review synthesises key papers on UUS utilisation and new town development. It indicates that the requirements of intensive use of land resources, accessibility reasons, avoidance of urban problems experienced in old cities, cultural and modernity considerations, and the goal of building smart, low-carbon and sustainable cities drive UUS utilisation in new developments. Underground spaces have been developed in new towns in various forms, with subway, underground parking facilities and underground utility infrastructure being the more prevalent forms of UUS utilisation, and UUS utilisation in new towns varying in scale. UUS utilisation for new developments may confront many challenges related to various issues: relationships between new towns and old city centres; compact and high-density urban forms; transit accessibility; awareness of the significance of UUS; balance between market forces and government intervention; coordination of development; full utilisation of UUS resources; and decision-making support. Existing practices used in UUS development provide lessons from which to learn.